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Abstract:

A process for making a latex emulsion suitable for use in a toner
composition includes co-emulsifying a bio-based resin with an insoluble
component, such as a pigment or wax, whereby the resin encapsulates the
insoluble component. The resulting latex, including the insoluble
component encapsulated in the resin, may then be utilized to form a
toner. The insoluble component may thus be included in toner particles,
which might otherwise be difficult to achieve, using emulsion aggregation
processes.

Claims:

1. A process comprising: contacting at least one polyester resin with at
least one organic solvent, the solvent being immiscible with water, to
form an organic phase; contacting the organic phase with a water phase
comprising a component insoluble in the organic phase selected from the
group consisting of wax dispersions, pigment dispersions, and
combinations thereof; mixing the organic phase and the water phase; and
evaporating the organic solvent to form a latex comprising the resin and
the insoluble component.

2. The process of claim 1, wherein the latex comprises the insoluble
component encapsulated by the at least one polyester resin.

8. The process of claim 1, wherein the water phase further comprises a
surfactant.

9. The process according to claim 1, wherein the latex has a solids
content from about 5% to about 50%, and a particle size from about 10 nm
to about 500 nm.

10. The process according to claim 1, wherein the evaporating is
completed by heating the mixture to a temperature of from about
40.degree. C. to about 90.degree. C.

11. A process comprising: contacting at least one polyester resin
comprising a bio-based resin comprising monomers selected from the group
consisting of a fatty dimer acid, a fatty dimer diol, D-isosorbide,
naphthalene dicarboxylate, azelaic acid, succinic acid, cyclohexanedioic
acid, naphthalene dicarboxylic acid, terephthalic acid, glutamic acid,
and combinations thereof, with at least one organic solvent immiscible
with water to form an organic phase; contacting the organic phase with a
water phase comprising a component insoluble in the organic phase
selected from the group consisting of wax dispersions, pigment
dispersions, and combinations thereof; mixing the organic phase and the
water phase; and evaporating the organic solvent to form a latex
comprising the insoluble component encapsulated by the resin.

12. The process of claim 11, wherein the at least one solvent is selected
from the group consisting of methyl ethyl ketone, dichloromethane, ethyl
acetate, hexane, and combinations thereof.

14. The process according to claim 11, wherein the wax is selected from
the group consisting of polyolefins, polybutene waxes, and combinations
thereof.

15. The process according to claim 11, wherein the latex has a solids
content from about 5% to about 50%, and a particle size from about 10 nm
to about 500 nm.

16. The process according to claim 11, wherein evaporating the organic
solvent occurs at a temperature of from about 40.degree. C. to about
90.degree. C.

17. process according to claim 1, further comprising: contacting the
latex with an optional colorant, an optional wax, and other toner
additives; aggregating the latex with the toner additives to form
aggregated particles; coalescing the aggregated particles to form toner
particles; and recovering the toner particles.

18. The process according to claim 11, further comprising contacting the
latex with an optional colorant, an optional wax and other toner
additives; aggregating the latex with the toner additives to form
aggregated particles; coalescing the aggregated particles to form toner
particles; and recovering the toner particles.

19. The process according to claim 6, wherein said polyolefins comprise a
polyethylene wax, a polypropylene wax, a functionalized polyethylene wax,
a functionalized polypropylene wax, a polyethylene/amide wax, a
polyethylenetetrafluoroethylene wax, a
polyethylenetetrafluoroethylene/amide wax or combinations thereof.

20. The process according to claim 14, wherein said polyolefins comprise
a polyethylene wax, a polypropylene wax, a functionalized polyethylene
wax, a functionalized polypropylene wax, a polyethylene/amide wax, a
polyethylenetetrafluoroethylene wax, a
polyethylenetetrafluoroethylene/amide wax or combinations thereof.

Description:

TECHNICAL FIELD

[0001] The present disclosure relates to processes for producing resin
emulsions useful in producing toners. More specifically, insoluble
materials, such as pigments and waxes, may be emulsified with bio-based
polyester resins, with the resulting latex utilized to prepare toners.

BACKGROUND

[0002] Numerous processes are within the purview of those skilled in the
art for the preparation of toners. Emulsion aggregation (EA) is one such
method. Emulsion aggregation toners may be used in forming print and/or
electrophotographic images. Emulsion aggregation techniques may involve
the formation of a polymer emulsion by heating a monomer and undertaking
a batch or semi-continuous emulsion polymerization, as disclosed in, for
example, U.S. Pat. No. 5,853,943, the disclosure of which is hereby
incorporated by reference in its entirety. Emulsion
aggregation/coalescing processes for the preparation of toners are
illustrated in a number of patents, such as U.S. Pat. Nos. 5,290,654,
5,278,020, 5,308,734, 5,344,738, 6,593,049, 6,743,559, 6,756,176,
6,830,860, 7,029,817, and 7,329,476, and U.S. Patent Application
Publication Nos. 2006/0216626, 2008/0107989, 2008/0107990, 2008/0236446,
and 2009/0047593. The disclosures of each of the foregoing patents are
hereby incorporated by reference in their entirety.

[0003] Polyester EA ultra low melt (ULM) toners have been prepared
utilizing amorphous and crystalline polyester resins as illustrated, for
example, in U.S. Patent Application Publication No. 2008/0153027, the
disclosure of which is hereby incorporated by reference in its entirety.

[0004] Many polymeric materials utilized in the formation of toners are
based upon the extraction and processing of fossil fuels, leading
ultimately to increases in greenhouse gases and accumulation of
non-degradable materials in the environment. Bio-based polyester resins
have been utilized to reduce the need of fossil fuel raw materials. An
example, as disclosed in co-pending U.S. Patent Application Publication
No. 2009/0155703, includes a toner having particles of a bio-based resin,
such as, for example, a semi-crystalline biodegradable polyester resin
including polyhydroxyalkanoates, wherein the toner is prepared by an
emulsion aggregation process. One issue that may arise with these
bio-based resins is it might be difficult to include otherwise insoluble
materials, including pigments and/or waxes, in the toner particles.

[0005] Enhanced methods for the production of resins remain desirable.

SUMMARY

[0006] The present disclosure provides latexes and the use of the latexes
in forming toners. Processes for producing these latexes and toners are
also provided.

[0007] In embodiments, a process of the present disclosure may include
contacting at least one polyester resin with at least one organic
solvent, the solvent being immiscible with water, to form an organic
phase; contacting the organic phase with a water phase including a
component insoluble in the organic phase selected from the group
consisting of wax dispersions, pigment dispersions, and combinations
thereof; and mixing the organic phase and the water phase; evaporating
the organic solvent to form a latex including the resin and the insoluble
component.

[0008] In other embodiments, a process of the present disclosure may
include contacting at least one polyester resin including a bio-based
resin including monomers such as a fatty dimer acid, a fatty dimer diol,
D-isosorbide, naphthalene dicarboxylate, azelaic acid, succinic acid,
cyclohexanedioic acid, naphthalene dicarboxylic acid, terephthalic acid,
glutamic acid, and combinations thereof, with at least one organic
solvent immiscible with water to form an organic phase; contacting the
organic phase with a water phase including a component insoluble in the
organic phase such as wax dispersions, pigment dispersions, and
combinations thereof; mixing the organic phase and the water phase; and
evaporating the organic solvent to form a latex including the insoluble
component encapsulated by the resin.

[0009] In yet other embodiments, a process of the present disclosure may
include contacting at least one polyester resin with at least one organic
solvent immiscible with water to form an organic phase; contacting the
organic phase with a water phase including a component insoluble in the
organic phase such as wax dispersions, pigment dispersions, and
combinations thereof; mixing the organic phase and the water phase;
evaporating the organic solvent to form a latex including the insoluble
component encapsulated by the resin; contacting the latex with an
optional colorant, an optional wax, and other toner additives;
aggregating the latex with the toner additives to form aggregated
particles; coalescing the aggregated particles to form toner particles;
and recovering the toner particles.

DETAILED DESCRIPTION

[0010] In embodiments, the present disclosure provides processes for
forming polyester latexes which may be utilized in forming a toner. For
EA toner, pigments and/or waxes may be added during the
emulsion-aggregation (EA) process. The incorporation of these otherwise
insoluble materials in the toner particles may prove difficult. For
example, pigments can be rejected during the EA process and/or washing
stage of the toner making process, thereby changing the final color of
the toner. The processes of the present disclosure may avoid some of
these issues.

[0011] In embodiments, the resin is a polyester resin. In some cases, some
insoluble components, such as a wax and/or pigment, may not be
incorporated into a toner particle. Co-emulsification of the wax or
pigment and the polyester resin may allow one to incorporate the wax into
a toner. While a conventional method for co-emulsification of two
components is to dissolve both of them in organic solvent, the organic
solvents that can be used for resin emulsification may not dissolve the
wax, such as a polyethylene wax, or pigment. Thus, in accordance with the
present disclosure, in embodiments a polyethylene wax dispersion may be
introduced into the water phase and mixed with resin/solvent solution
under homogenization.

[0012] Bio-based resins or products, as used herein, in embodiments,
include commercial and/or industrial products (other than food or feed)
that may be composed, in whole or in significant part, of biological
products or renewable domestic agricultural materials (including plant,
animal, or marine materials) and/or forestry materials as defined by the
U.S. Office of the Federal Environmental Executive.

Bio-Based Resins

[0013] In embodiments, resins utilized to form latexes suitable for
forming toners in accordance with the present disclosure may include
bio-based resins. As used herein, a bio-based resin is a resin or resin
formulation derived from a biological source such as vegetable oil
instead of petrochemicals. As renewable polymers with low environmental
impact, their principal advantages include that they reduce reliance on
finite resources of petrochemicals, and they sequester carbon from the
atmosphere. A bio-resin includes, in embodiments, for example, a resin
wherein at least a portion of the resin is derived from a natural
biological material, such as animal, plant, combinations thereof, and the
like.

[0015] Examples of amorphous bio-based polymeric resins which may be
utilized include polyesters derived from monomers including a fatty dimer
acid or diol of soya oil, D-isosorbide, and/or amino acids such as
L-tyrosine and glutamic acid as described in U.S. Pat. Nos. 5,959,066,
6,025,061, 6,063,464, and 6,107,447, and U.S. Patent Application
Publication Nos. 2008/0145775 and 2007/0015075, the disclosures of each
of which are hereby incorporated by reference in their entirety.

[0017] In embodiments, the polyester resin may be formed by the
polycondensation of isosorbide with either succinic acid or azelaic acid,
or a mixture of succinic acid and azelaic acid in the presence of a
catalyst. The isosorbide may be selected in an amount of, for example,
from about 40 to about 60 mol %, such as from about 42 to about 55 mol %,
or from about 45 to about 53 mol % of the polyester resin. The total
amount of diacid may be selected in an amount of, for example, from about
40 to about 60 mol %, such as from about 42 to about 55 mol %, or from
about 45 to about 53 mol % of the polyester resin. When the diacid is a
combination of succinic acid and azelaic acid, the amount of succinic
acid may be selected in an amount of, for example, from about 30 to about
60 mol % of the polyester resin, and the amount of azelaic acid may be
selected in an amount of, for example, from greater than 0 to about 20
mol % of the polyester resin.

[0018] Polycondensation catalysts include tetraalkyl titanates such as
titanium (iv) butoxide or titanium (iv) iso-propoxide; dialkyltin oxides
such as dibutyltin oxide; tetraalkyltins such as dibutyltin dilaurate;
dialkyltin oxide hydroxides such as butyltin oxide hydroxide; aluminum
alkoxides; alkyl zinc; dialkyl zinc; zinc oxide; stannous oxide; and
combinations thereof. The catalysts may be used in amounts of, for
example, from about 0.001 mol % to about 0.55 mol % based on the starting
diacid or diester used to generate the polyester resin.

[0019] In other embodiments, non-bio-based polyester resins may also be
used. Suitable non-bio-based polyester resins include, for example,
sulfonated, non-sulfonated, crystalline, amorphous, combinations thereof,
and the like. The polyester resins may be linear, branched, combinations
thereof, and the like. Polyester resins may include, in embodiments,
those resins described in U.S. Pat. Nos. 6,593,049 and 6,756,176, the
disclosures of each of which are hereby incorporated by reference in
their entirety. Suitable resins may also include a mixture of an
amorphous polyester resin and a crystalline polyester resin as described
in U.S. Pat. No. 6,830,860, the disclosure of which is hereby
incorporated by reference in its entirety.

[0020] The polyester resin may have a number average molecular weight
(Mn), as measured by gel permeation chromatography (GPC) of, for
example, from about 1,000 to about 50,000, such as from about 2,000 to
about 25,000, and a weight average molecular weight (Mw) of, for
example, from about 2,000 to about 100,000, such as from about 3,000 to
about 14,000, as determined by GPC using polystyrene standards. The
molecular weight distribution (Mw/Mn) of the polyester resin
may be, for example, from about 1 to about 6, such as from about 1.5 to
about 4.

[0021] The polyester resin may have a glass transition temperature (Tg)
of, for example, from about 30° C. to about 120° C., such
as from about 40° C. to about 90° C., or from about
45° C. to about 75° C. Adding more azelaic acid relative to
the amount of succinic acid in the polymer formulation will decreases the
glass transition temperature of the resin.

[0022] The polyester resin may have a softening point (Ts) of, for
example, from about 90° C. to about 150° C., such as from
about 95° C. to about 135° C., or from about 100° C.
to about 120° C. Different softening points may produce toners
exhibiting different gloss levels. For example, in some embodiments,
resins having a softening point of 101° C. to 103° C.
produce toners having a higher gloss than toners produced with resins
having a softening point of 105° C. or higher.

[0023] The polyester resin may have an acid value from about 2 to about 30
mgKOH/g, such as from about 9 to about 16 mgKOH/g, or from about 10 to
about 14 mgKOH/g. The acid value (or "neutralization number" or "acid
number" or "acidity") may be measured by dissolving a known amount of
polymer sample in an organic solvent and titrating with a solution of
potassium hydroxide (KOH) with known concentration and with
phenolphthalein as a color indicator. The acid number is the mass of
potassium hydroxide in milligrams that is required to neutralize one gram
of chemical substance. For the polyester resins, the acid number is the
measure of the amount of carboxylic acid groups in a polyester molecule.

Colorants

[0024] As noted above, in embodiments, an otherwise insoluble material,
including a pigment or other colorant, may be added during formation of
the polyester latex. As the colorant to be added, various known suitable
colorants, such as dyes, pigments, mixtures of dyes, mixtures of
pigments, mixtures of dyes and pigments, and the like, may be included in
the toner. The colorant may be added in amounts from about 0.1 to about
35 weight percent of the toner, in embodiments from about 1 to about 15
weight percent of the toner, in embodiments from about 3 to about 10
weight percent of the toner.

[0027] As also noted above, in embodiments other insoluble materials,
including a wax, may be added in addition to, or instead of, a pigment,
during formation of the polyester latex. A single type of wax or a
combination of two or more different waxes may be added. A single wax may
be added to toner formulations, for example, to improve particular toner
properties, such as toner particle shape, presence and amount of wax on
the toner particle surface, charging and/or fusing characteristics,
gloss, stripping, offset properties, and the like. Alternatively, a
combination of waxes can be added to provide multiple properties to the
toner composition.

[0028] When included, the wax may be present in an amount of, for example,
from about 1 weight percent to about 25 weight percent of the toner
particles, in embodiments from about 5 weight percent to about 20 weight
percent of the toner particles.

[0029] The wax may include any of the various waxes conventionally used in
emulsion aggregation toner compositions. Waxes that may be selected
include waxes having, for example, an average molecular weight from about
500 to about 20,000, in embodiments from about 1,000 to about 10,000.
Waxes that may be used include, for example, polyolefins such as
polyethylene including linear polyethylene waxes and branched
polyethylene waxes, polypropylene including linear polypropylene waxes
and branched polypropylene waxes, functionalized polyethylene waxes,
functionalized polypropylene waxes, polyethylene/amide,
polyethylenetetrafluoroethylene, polyethylenetetrafluoroethylene/amide,
and polybutene waxes such as commercially available from Allied Chemical
and Petrolite Corporation, for example POLYWAX® polyethylene waxes
such as commercially available from Baker Petrolite, wax emulsions
available from Michaelman, Inc. and the Daniels Products Company, EPOLENE
N-15® commercially available from Eastman Chemical Products, Inc., and
VISCOL 550-P®, a low weight average molecular weight polypropylene
available from Sanyo Kasei K. K.; plant-based waxes, such as carnauba
wax, rice wax, candelilla wax, sumacs wax, and jojoba oil; animal-based
waxes, such as beeswax; mineral-based waxes and petroleum-based waxes,
such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline
wax such as waxes derived from distillation of crude oil, silicone waxes,
mercapto waxes, polyester waxes, urethane waxes; modified polyolefin
waxes (such as a carboxylic acid-terminated polyethylene wax or a
carboxylic acid-terminated polypropylene wax); Fischer-Tropsch wax; ester
waxes obtained from higher fatty acid and higher alcohol, such as stearyl
stearate and behenyl behenate; ester waxes obtained from higher fatty
acid and monovalent or multivalent lower alcohol, such as butyl stearate,
propyl oleate, glyceride monostearate, glyceride distearate, and
pentaerythritol tetra behenate; ester waxes obtained from higher fatty
acid and multivalent alcohol multimers, such as diethylene glycol
monostearate, dipropylene glycol distearate, diglyceryl distearate, and
triglyceryl tetrastearate; sorbitan higher fatty acid ester waxes, such
as sorbitan monostearate, and cholesterol higher fatty acid ester waxes,
such as cholesteryl stearate. Examples of functionalized waxes that may
be used include, for example, amines, amides, for example AQUA SUPERSLIP
6550®, SUPERSLIP 6530® available from Micro Powder Inc.,
fluorinated waxes, for example POLYFLUO 190®, POLYFLUO 200®,
POLYSILK 19®, POLYSILK 14® available from Micro Powder Inc., mixed
fluorinated, amide waxes, such as aliphatic polar amide functionalized
waxes; aliphatic waxes consisting of esters of hydroxylated unsaturated
fatty acids, for example MICROSPERSION 19® also available from Micro
Powder Inc., imides, esters, quaternary amines, carboxylic acids or
acrylic polymer emulsion, for example JONCRYL 74®, 89®, 130®,
537®, and 538®, all available from SC Johnson Wax, and chlorinated
polypropylenes and polyethylenes available from Allied Chemical and
Petrolite Corporation and SC Johnson wax. Mixtures and combinations of
the foregoing waxes may also be used in embodiments. Waxes may be
included as, for example, fuser roll release agents. In embodiments, the
waxes may be crystalline or non-crystalline.

[0030] In embodiments, the wax may include particles having a size from
about 100 nm to about 300 nm.

Solvents

[0031] As noted above, solvents may be used to form the latex including
the bio-based resin and insoluble materials, such as a pigment and/or
wax. These solvents may include, for example, ethyl acetate, methyl ethyl
ketone, dichloromethane, hexane, combinations thereof, and the like.

[0032] In embodiments, the solvents may be utilized in an amount of, for
example, from about 25 weight percent to about 5000% weight percent of
the resin, in embodiments from about 50 weight percent to about 2000%
weight percent of the resin, in other embodiments from about 100 weight
percent to about 500% weight percent of the resin.

[0033] In embodiments, an emulsion formed in accordance with the present
disclosure may also include water, in embodiments, de-ionized water
(DIW), in amounts from about 30% to about 95%, in embodiments, from about
35% to about 80%.

[0034] The particle size of the emulsion may be from about 50 nm to about
300 nm, in embodiments from about 100 nm to about 250 nm.

Neutralizing Agent

[0035] In embodiments, the resin and insoluble components, such as a
pigment and/or wax, may be mixed with a weak base or neutralizing agent.
In embodiments, the neutralizing agent may be used to neutralize acid
groups in the resins, so a neutralizing agent herein may also be referred
to as a "basic neutralization agent." Any suitable basic neutralization
reagent may be used in accordance with the present disclosure. In
embodiments, suitable basic neutralization agents may include both
inorganic basic agents and organic basic agents. Suitable basic agents
may include ammonium hydroxide, potassium hydroxide, sodium hydroxide,
sodium carbonate, sodium bicarbonate, lithium hydroxide, potassium
carbonate, combinations thereof, and the like. Suitable basic agents may
also include monocyclic compounds and polycyclic compounds having at
least one nitrogen atom, such as, for example, secondary amines, which
include aziridines, azetidines, piperazines, piperidines, pyridines,
bipyridines, terpyridines, dihydropyridines, morpholines,
N-alkylmorpholines, 1,4-diazabicyclo[2.2.2]octanes,
1,8-diazabicycloundecanes, 1,8-diazabicycloundecenes, dimethylated
pentylamines, trimethylated pentylamines, pyrimidines, pyrroles,
pyrrolidines, pyrrolidinones, indoles, indolines, indanones,
benzindazones, imidazoles, benzimidazoles, imidazolones, imidazolines,
oxazoles, isoxazoles, oxazolines, oxadiazoles, thiadiazoles, carbazoles,
quinolines, isoquinolines, naphthyridines, triazines, triazoles,
tetrazoles, pyrazoles, pyrazolines, and combinations thereof. In
embodiments, the monocyclic and polycyclic compounds may be unsubstituted
or substituted at any carbon position on the ring.

[0036] The basic agent may be utilized in an amount from about 0.001
weight percent to 50 weight percent of the resin, in embodiments from
about 0.01 weight percent to about 25 weight percent of the resin, in
embodiments from about 0.1 weight percent to 5 weight percent of the
resin. In embodiments, the neutralizing agent may be added in the form of
an aqueous solution. In other embodiments, the neutralizing agent may be
added in the form of a solid.

[0037] Utilizing the above basic neutralization agent in combination with
a resin possessing acid groups, a neutralization ratio from about 25% to
about 500% may be achieved, in embodiments from about 50% to about 300%.
In embodiments, the neutralization ratio may be calculated as the molar
ratio of basic groups provided with the basic neutralizing agent to the
acid groups present in the resin multiplied by 100%.

[0038] As noted above, the basic neutralization agent may be added to a
resin possessing acid groups. The addition of the basic neutralization
agent may thus raise the pH of an emulsion including a resin possessing
acid groups from about 8 to about 14, in embodiments, from about 9 to
about 11. The neutralization of the acid groups may, in embodiments,
enhance formation of the emulsion.

Surfactants

[0039] In embodiments, a surfactant may be added to the resin, insoluble
component such as pigment and/or wax, and solvent to form the emulsion.

[0040] Where utilized, a resin emulsion may include one, two, or more
surfactants. The surfactants may be selected from ionic surfactants and
nonionic surfactants. Anionic surfactants and cationic surfactants are
encompassed by the term "ionic surfactants." In embodiments, the
surfactant may be added as a solid or as a solution with a concentration
from about 5% to about 100% (pure surfactant) by weight, in embodiments,
from about 10% to about 95 weight percent. In embodiments, the surfactant
may be utilized so that it is present in an amount from about 0.01 weight
percent to about 20 weight percent of the resin, in embodiments, from
about 0.1 weight percent to about 16 weight percent of the resin, in
other embodiments, from about 1 weight percent to about 14 weight percent
of the resin.

[0041] Anionic surfactants which may be utilized include sulfates and
sulfonates, sodium dodecylsulfate (SDS), sodium dodecylbenzene sulfonate,
sodium dodecylnaphthalene sulfate, dialkyl benzenealkyl sulfates and
sulfonates, acids such as abitic acid available from Aldrich, NEOGEN
R®, NEOGEN SC® obtained from Daiichi Kogyo Seiyaku, combinations
thereof, and the like. Other suitable anionic surfactants include, in
embodiments, DOWFAX®® 2A1, an alkyldiphenyloxide disulfonate from
The Dow Chemical Company, and/or TAYCA POWER BN2060 from Tayca
Corporation (Japan), which are branched sodium dodecylbenzene sulfonates.
Combinations of these surfactants and any of the foregoing anionic
surfactants may be utilized in embodiments.

[0044] In accordance with the present disclosure, instead of adding an
insoluble component such as a pigment or wax to a toner formulation as a
separate dispersion, the insoluble component may be encapsulated in resin
latex particles. For example, in embodiments, the insoluble component may
be encapsulated in the latex by co-emulsifying the pigment and/or wax
with the bio-based resin through solvent flash or phase inversion
emulsification (PIE) which, in turn, may be solvent based or solvent
less. While the insoluble component may be introduced as part of the
water phase, the insoluble component should move into and remain in the
organic phase (the dissolved or melted resin). Therefore, once the
pigment and/or wax is encased in the resin, the pigment and/or wax may be
successfully incorporated in the toner particles by aggregating the latex
containing the pigment and/or wax.

[0045] More than one resin may be utilized in forming the latex. As noted
above, the resin may be a bio-based resin. In further embodiments, the
resin may be a bio-based resin, optionally in combination with an
amorphous resin and/or a mixture of amorphous and crystalline resins.

[0046] In embodiments, the insoluble component may be introduced as part
of the water phase. A process of the present disclosure may thus include
contacting at least one resin with a water immiscible solvent to form a
resin mixture, adding the mixture into a water phase under homogenization
to form a latex emulsion, where the water phase includes an otherwise
insoluble material dispersion such as a pigment dispersion or wax
dispersion, optionally a surfactant, and optionally a neutralizing agent
to neutralize the acid groups of the resin, distilling the latex to
remove a water/solvent mixture in the distillate and producing a high
quality latex.

[0047] In the emulsification process, the polyester resins may be
dissolved in a solvent at a concentration from about 1 weight percent to
about 85 weight percent resin in solvent, in embodiments from about 5
weight percent to about 60 weight percent resin in solvent. The resin in
a solvent may be referred to, in embodiments, as an organic phase or an
organic solvent phase.

[0048] A fixed amount of base solution (such as ammonium hydroxide) is
then into a water phase including de-ionized water (DIW) in combination
an otherwise insoluble material dispersion such as a pigment dispersion
or wax dispersion, followed by contacting the organic solvent phase and
the water phase to form a uniform dispersion of polyester particles in
water through phase inversion. The solvents remain in both the polyester
particles and water phase at this stage. Through vacuum distillation, the
solvents are stripped off.

[0049] In embodiments, the optional surfactant utilized may be any of the
surfactants mentioned herein above to ensure that proper resin
neutralization occurs and leads to a high quality latex with low coarse
content.

[0050] Stirring is utilized when contacting the water phase and organic
solvent phase. In embodiments, the water phase can be added into the
organic solvent phase. In other embodiments, the organic solvent phase
can be added into the water phase. Any suitable stirring device may be
utilized. In embodiments, the stirring may be at a speed from about 10
revolutions per minute (rpm) to about 50,000 rpm, in embodiments from
about 20 rpm to about 20,000 rpm, in other embodiments from about 50 rpm
to about 10,000 rpm. The stirring need not be at a constant speed, but
may be varied. For example, as the heating of the mixture becomes more
uniform, the stirring rate may be increased. In embodiments, a
homogenizer (that is, a high shear device), may be utilized to form the
emulsion, but in other embodiments, the process of the present disclosure
may take place without the use of a homogenizer. Where utilized, a
homogenizer may operate at a rate from about 3,000 rpm to about 10,000
rpm.

[0051] Following phase inversion, additional surfactant, water, and/or
aqueous alkaline solution may optionally be added to dilute the phase
inversed emulsion, although this is not required.

[0052] Regardless of the process utilized, after removal of the organic
solvent, the pigment and/or wax may be encapsulated in resin latex
particles because the insoluble compound, such as the pigment and/or wax,
remains in the organic phase (the dissolved or melted resin), rather than
the water phase.

[0053] The insoluble compound, now encased in the resin, may then be
incorporated into toner particles by aggregating the insoluble compound
containing latex. For example the latex emulsions of the present
disclosure may be utilized to produce particles that are suitable for
emulsion aggregation ultra low melt processes.

[0054] The emulsified resin particles in the aqueous medium may have a
submicron size, for example of about 1 μm or less, in embodiments
about 500 nm or less, such as from about 10 nm to about 500 nm, in
embodiments from about 50 nm to about 400 nm, in other embodiments from
about 100 nm to about 300 nm, in some embodiments about 200 nm.
Adjustments in particle size can be made by modifying the ratio of water
to resin, the neutralization ratio, solvent concentration, and solvent
composition.

[0055] The coarse content of the latex of the present disclosure may be
from about 0.01 weight percent to about 5 weight percent, in embodiments,
from about 0.1 weight percent to about 3 weight percent. The solids
content of the latex of the present disclosure may be from about 5 weight
percent to about 50 weight percent, in embodiments, from about 20 weight
percent to about 40 weight percent.

[0056] In embodiments, the molecular weight of the resin emulsion
particles of the present disclosure may be from about 18,000 grams/mole
to about 26,000 grams/mole, in embodiments from about 21,500 grams/mole
to about 25,000 grams/mole, in embodiments from about 23,000 grams/mole
to about 24,000 grams/mole.

[0057] The resulting resin particles in the latex may possess the pigment
in an amount from about 0.1% by weight to about 35% by weight of the
resin particle, in embodiments from about 1% by weight to about 20% by
weight of the resin particle. Similarly, the resulting resin particles in
the latex may possess the wax in an amount from about 0.1% by weight to
about 25% by weight of the resin particle, in embodiments from about 5%
by weight to about 20% by weight of the resin particle.

Toner

[0058] Once the resin mixture has been contacted with water to form an
emulsion and the solvent removed from this mixture as described above,
the resulting latex may then be utilized to form a toner by any method
within the purview of those skilled in the art. The latex emulsion may be
contacted with other optional resins, colorants and/or waxes, optionally
in a dispersion, and other additives to form an ultra low melt toner by a
suitable process, in embodiments, an emulsion aggregation and coalescence
process.

Toner Preparation

[0059] Toner particles may be prepared with the above latex, including
resin-encapsulated insoluble components, by any method within the purview
of one skilled in the art. Although embodiments relating to toner
particle production are described below with respect to emulsion
aggregation processes, any suitable method of preparing toner particles
may be used, including chemical processes, such as suspension and
encapsulation processes disclosed in U.S. Pat. Nos. 5,290,654 and
5,302,486, the disclosures of each of which are hereby incorporated by
reference in their entirety. In embodiments, toner compositions and toner
particles may be prepared by aggregation and coalescence processes in
which small-size resin particles are aggregated to the appropriate toner
particle size and then coalesced to achieve the final toner particle
shape and morphology.

[0060] In embodiments, toner compositions may be prepared by emulsion
aggregation processes, such as a process that includes aggregating a
mixture of an optional colorant, an optional wax and any other desired or
required additives, and emulsions including the resin-encapsulated toner
components described above, optionally in surfactants as described above,
and then coalescing the aggregate mixture. A mixture may be prepared by
adding a colorant and optionally a wax or other materials, which may also
be optionally in a dispersion(s) including a surfactant, to the emulsion,
which may be a mixture of two or more emulsions containing the resin. The
pH of the resulting mixture may be adjusted by an acid such as, for
example, acetic acid, nitric acid or the like. In embodiments, the pH of
the mixture may be adjusted to from about 2 to about 5. Additionally, in
embodiments, the mixture may be homogenized. If the mixture is
homogenized, homogenization may be accomplished by mixing at about 600 to
about 6,000 revolutions per minute. Homogenization may be accomplished by
any suitable means, including, for example, an IKA ULTRA TURRAX T50 probe
homogenizer.

[0061] Following the preparation of the above mixture, an aggregating
agent may be added to the mixture. Any suitable aggregating agent may be
utilized to form a toner. Suitable aggregating agents include, for
example, aqueous solutions of a divalent cation or a multivalent cation
material. The aggregating agent may be, for example, an inorganic
cationic aggregating agent such as polyaluminum halides such as
polyaluminum chloride (PAC), or the corresponding bromide, fluoride, or
iodide, polyaluminum silicates such as polyaluminum sulfosilicate (PASS),
and water soluble metal salts including aluminum chloride, aluminum
nitrite, aluminum sulfate, potassium aluminum sulfate, calcium acetate,
calcium chloride, calcium nitrite, calcium oxylate, calcium sulfate,
magnesium acetate, magnesium nitrate, magnesium sulfate, zinc acetate,
zinc nitrate, zinc sulfate, zinc chloride, zinc bromide, magnesium
bromide, copper chloride, copper sulfate, and combinations thereof. In
embodiments, the aggregating agent may be added to the mixture at a
temperature that is below the glass transition temperature (Tg) of the
resin.

[0063] Other suitable aggregating agents also include, but are not limited
to, tetraalkyl titinates, dialkyltin oxide, tetraalkyltin oxide
hydroxide, dialkyltin oxide hydroxide, aluminum alkoxides, alkyl zinc,
dialkyl zinc, zinc oxides, stannous oxide, dibutyltin oxide, dibutyltin
oxide hydroxide, tetraalkyl tin, combinations thereof, and the like.
Where the aggregating agent is a polyion aggregating agent, the agent may
have any desired number of polyion atoms present. For example, in
embodiments, suitable polyaluminum compounds have from about 2 to about
13, in other embodiments, from about 3 to about 8, aluminum ions present
in the compound.

[0064] The aggregating agent may be added to the mixture utilized to form
a toner in an amount of, for example, from about 0 to about 10 weight
percent, in embodiments from about 0.2 to about 8 weight percent, in
other embodiments from about 0.5 to about 5 weight percent, of the resin
in the mixture. This should provide a sufficient amount of agent for
aggregation.

[0065] The particles may be permitted to aggregate until a predetermined
desired particle size is obtained. A predetermined desired size refers to
the desired particle size to be obtained as determined prior to
formation, and the particle size being monitored during the growth
process until such particle size is reached. Samples may be taken during
the growth process and analyzed, for example with a Coulter Counter, for
average particle size. The aggregation thus may proceed by maintaining
the elevated temperature, or slowly raising the temperature to, for
example, from about 40° C. to about 100° C., and holding
the mixture at this temperature for a time from about 0.5 hours to about
6 hours, in embodiments from about hour 1 to about 5 hours, while
maintaining stirring, to provide the aggregated particles. Once the
predetermined desired particle size is reached, then the growth process
is halted.

[0066] The growth and shaping of the particles following addition of the
aggregation agent may be accomplished under any suitable conditions. For
example, the growth and shaping may be conducted under conditions in
which aggregation occurs separate from coalescence. For separate
aggregation and coalescence stages, the aggregation process may be
conducted under shearing conditions at an elevated temperature, for
example from about 40° C. to about 90° C., in embodiments
from about 45° C. to about 80° C., which may be below the
glass transition temperature of the resin as discussed above.

[0067] Once the desired final size of the toner particles is achieved, the
pH of the mixture may be adjusted with a base to a value from about 3 to
about 10, and in embodiments from about 5 to about 9. The adjustment of
the pH may be utilized to freeze, that is to stop, toner growth. The base
utilized to stop toner growth may include any suitable base such as, for
example, alkali metal hydroxides such as, for example, sodium hydroxide,
potassium hydroxide, ammonium hydroxide, combinations thereof, and the
like. In embodiments, ethylene diamine tetraacetic acid (EDTA) may be
added to help adjust the pH to the desired values noted above.

[0068] In embodiments, the final size of the toner particles may be from
about 2 μm to about 12 μm, in embodiments from about 3 μm to
about 10 μm.

Shell Resin

[0069] In embodiments, after aggregation, but prior to coalescence, a
resin coating may be applied to the aggregated particles to form a shell
thereover. Any resin described above may be utilized as the shell. In
embodiments, a polyester amorphous resin latex as described above may be
included in the shell. In embodiments, the polyester amorphous resin
latex described above may be combined with a different resin, and then
added to the particles as a resin coating to form a shell.

[0070] In embodiments, resins which may be utilized to form a shell
include, but are not limited to, the amorphous resins described above. In
embodiments, an amorphous resin which may be utilized to form a shell in
accordance with the present disclosure includes an amorphous polyester.
Multiple resins may be utilized in any suitable amounts.

[0071] The shell resin may be applied to the aggregated particles by any
method within the purview of those skilled in the art. In embodiments,
the resins utilized to form the shell may be in an emulsion including any
surfactant described above. The emulsion possessing the resins may be
combined with the aggregated particles described above so that the shell
forms over the aggregated particles.

[0072] The formation of the shell over the aggregated particles may occur
while heating to a temperature from about 30° C. to about
80° C., in embodiments from about 35° C. to about
70° C. The formation of the shell may take place for a period of
time from about 5 minutes to about 10 hours, in embodiments from about 10
minutes to about 5 hours.

[0073] The shell may be present in an amount from about 1 percent by
weight to about 80 percent by weight of the toner components, in
embodiments from about 10 percent by weight to about 40 percent by weight
of the toner components, in still further embodiments from about 20
percent by weight to about 35 percent by weight of the toner components.

Coalescence

[0074] Following aggregation to the desired particle size and application
of any optional shell, the particles may then be coalesced to the desired
final shape, the coalescence being achieved by, for example, heating the
mixture to a temperature from about 45° C. to about 100°
C., in embodiments from about 55° C. to about 99° C., which
may be at or above the glass transition temperature of the resins
utilized to form the toner particles, and/or reducing the stirring, for
example to from about 1000 rpm to about 100 rpm, in embodiments from
about 800 rpm to about 200 rpm. Coalescence may be accomplished over a
period from about 0.01 to about 9 hours, in embodiments from about 0.1 to
about 4 hours.

[0075] After aggregation and/or coalescence, the mixture may be cooled to
room temperature, such as from about 20° C. to about 25° C.
The cooling may be rapid or slow, as desired. A suitable cooling method
may include introducing cold water to a jacket around the reactor. After
cooling, the toner particles may be optionally washed with water, and
then dried. Drying may be accomplished by any suitable method for drying
including, for example, freeze-drying.

Additives

[0076] In embodiments, the toner particles may also contain other optional
additives, as desired or required. For example, the toner may include
positive or negative charge control agents, for example in an amount from
about 0.1 to about 10 weight percent of the toner, in embodiments from
about 1 to about 3 weight percent of the toner. Examples of suitable
charge control agents include quaternary ammonium compounds inclusive of
alkyl pyridinium halides; bisulfates; alkyl pyridinium compounds,
including those disclosed in U.S. Pat. No. 4,298,672, the disclosure of
which is hereby incorporated by reference in its entirety; organic
sulfate and sulfonate compositions, including those disclosed in U.S.
Pat. No. 4,338,390, the disclosure of which is hereby incorporated by
reference in its entirety; cetyl pyridinium tetrafluoroborates; distearyl
dimethyl ammonium methyl sulfate; aluminum salts such as BONTRON E84®
or E88® (Orient Chemical Industries, Ltd.); combinations thereof, and
the like.

[0077] There can also be blended with the toner particles external
additive particles after formation including flow aid additives, which
additives may be present on the surface of the toner particles. Examples
of these additives include metal oxides such as titanium oxide, silicon
oxide, aluminum oxides, cerium oxides, tin oxide, mixtures thereof, and
the like; colloidal and amorphous silicas, such as AEROSIL®, metal
salts and metal salts of fatty acids inclusive of zinc stearate, calcium
stearate, or long chain alcohols such as UNILIN 700, and mixtures
thereof.

[0078] In general, silica may be applied to the toner surface for toner
flow, triboelectric charge enhancement, admix control, improved
development and transfer stability, and higher toner blocking
temperature. TiO2 may be applied for improved relative humidity (RH)
stability, triboelectric charge control and improved development and
transfer stability. Zinc stearate, calcium stearate and/or magnesium
stearate may optionally also be used as an external additive for
providing lubricating properties, developer conductivity, triboelectric
charge enhancement, enabling higher toner charge and charge stability by
increasing the number of contacts between toner and carrier particles. In
embodiments, a commercially available zinc stearate known as Zinc
Stearate L, obtained from Ferro Corporation, may be used. The external
surface additives may be used with or without a coating.

[0079] Each of these external additives may be present in an amount from
about 0.1 weight percent to about 5 weight percent of the toner, in
embodiments from about 0.25 weight percent to about 3 weight percent of
the toner, although the amount of additives can be outside of these
ranges. In embodiments, the toners may include, for example, from about
0.1 weight percent to about 5 weight percent titania, from about 0.1
weight percent to about 8 weight percent silica, and from about 0.1
weight percent to about 4 weight percent zinc stearate.

[0080] Suitable additives include those disclosed in U.S. Pat. Nos.
3,590,000, and 6,214,507, the disclosures of each of which are hereby
incorporated by reference in their entirety.

[0081] It has been found that toners produced in accordance with the
present disclosure have little rejection of the pigments and/or waxes
that would otherwise be insoluble in the latex utilized to form the toner
particles. Thus, for example, at least about 80% by weight of the pigment
or wax utilized in forming the latex may be present in a toner later
produced with the latex, in embodiments from about 90% by weight to about
100% by weight of the pigment or wax utilized in forming the latex may be
present in a toner later produced with the latex, in embodiments from
about 92% by weight to about 98% by weight of the pigment or wax utilized
in forming the latex may be present in a toner later produced with the
latex.

[0082] The following Examples are being submitted to illustrate
embodiments of the present disclosure. These Examples are intended to be
illustrative only and are not intended to limit the scope of the present
disclosure. Also, parts and percentages are by weight unless otherwise
indicated. As used herein, "room temperature" refers to a temperature
from about 20° C. to about 25° C.

EXAMPLES

Comparative Example 1

[0083] Preparation of an emulsion aggregation (EA) toner, where a pigment
dispersion was added separately in the toner formulation. Into a 1000 ml
glass beaker equipped with a magnetic stir bar and a hotplate, about
296.74 grams of an emulsion containing 100% by weight of a bio-based
resin made from 50% isosorbide, 45% succinic acid, and 5% azelaic acid,
about 20.45 grams of a cyan pigment dispersion (Pigment Blue 15:3 (17% by
weight), and about 2.91 grams of DOWFAX® 2A1, an alkyldiphenyloxide
disulfonate (commercially available from the Dow Chemical Company) (about
47% by weight). The above mixture was cooled to about 8° C. using
an ice bath. After the pH was adjusted to about 4.2, about 22.29 grams of
Al2(SO4).sub.3 solution (about 1% by weight) was added as a
flocculent under homogenization. The temperature of the mixture was
increased to about 17.9° C. with stirring at about 900 revolutions
per minute (rpm). The particle size was monitored with a Coulter Counter
until the core particles reached a volume average particle size of about
5.83 μm, with a volume average Geometric Size Distribution (GSDv) of
about 1.27.

[0084] A sample taken at this point visibly showed severe pigment
rejection.

[0085] The pH of the reaction slurry was then increased to about 7.5 using
about 1.72 grams of ethylene diamine tetraacetic acid (EDTA) about (39%
by weight) and NaOH (about 4% by weight) to freeze, i.e., stop, the toner
growth. After freezing, the reaction mixture was heated to about
40.7° C., and the pH was reduced to about 7.01 for coalescence.
The toner was quenched after coalescence, and it had a final particle
size of about 5.48 microns, a GSDv of about 1.33, and a circularity of
about 0.965.

[0086] A sample of the above toner slurry was taken and settled in a glass
vial. The sample had severe pigment rejection, and toner having a very
light color settled at the bottom of the vial.

Example 1

[0087] Preparation of latex with pigment encapsulated in bio-resin
particles. About 56.7 grams of the 100% bio based resin described above
in Comparative Example 1 was measured into a 2 liter beaker containing
about 500 grams of dichloromethane. The mixture was stirred at about 300
revolutions per minute at room temperature to dissolve the resin in the
dichloromethane, thereby forming a resin solution.

[0088] About 21.16 grams of the cyan pigment dispersion described above in
Comparative Example 1 (about 17% by weight containing 9 parts per hundred
(pph) of a branched sodium dodecyl benzene sulfonate surfactant from
Tayca Corporation (Japan)) together with about 1.14 grams of sodium
bicarbonate and about 2.41 grams DOWFAX® 2A1, an alkyldiphenyloxide
disulfonate (commercially available from the Dow Chemical Company) (about
47% by weight) was measured into a 3 liter Pyrex glass flask reactor
containing about 300 grams of deionized water, thereby forming a water
solution. Homogenization of said water solution in said 3 liter glass
flask reactor was commenced with an IKA Ultra Turrax T50 homogenizer
operating at about 4,000 revolutions per minute. The resin solution was
then slowly poured into the water solution. As the mixture continued to
be homogenized, the homogenizer speed was increased to about 8,000
revolutions per minute and homogenization was carried out at these
conditions for about 30 minutes. Upon completion of homogenization, the
glass flask reactor and its contents were placed in a heating mantle and
connected to a distillation device.

[0089] The mixture was stirred at about 200 revolutions per minute and the
temperature of the mixture was increased to about 50° C. at a rate
of about 1° C. per minute to distill off the dichloromethane from
the mixture. Stirring continued at about 50° C. for about 180
minutes, followed by cooling at about 2° C. per minute to room
temperature. The product was screened through a 25 micron sieve.

[0090] The resulting resin emulsion included about 19.39 percent by weight
solids in water, with an average particle size of 141.2 nm.

Example 2

[0091] Preparation of EA toner with pigment encapsulated in a bio-resin
emulsion. Into a 1000 ml glass beaker equipped with a magnetic stir bar
and a hotplate, about 3.07 grams DOWFAX® 2A1, an alkyldiphenyloxide
disulfonate (commercially available from the Dow Chemical Company) (about
47% by weight), was combined with about 304.05 grams of the latex from
Example 1, including the bio-based resin with encapsulated cyan pigment.
The mixture was cooled to about 8° C. using an ice bath. After the
pH of the components was adjusted to about 4.2, about 23.02 grams of
Al2(SO4).sub.3 solution (1% by weight) was added as a
flocculent under homogenization. The temperature of the mixture was
increased to about 19° C. with mixing at about 900 rpm. The
particle size was monitored with a Coulter Counter until the core
particles reached a volume average particle size of about 6.15 μm with
a GSDv of about 1.26.

[0092] A sample taken at this point had clear mother liquor. The pH of the
reaction slurry was then increased to about 7.3 using about 1.79 grams
EDTA (about 39% by weight) and NaOH (about 4% by weight) to freeze, i.e.,
stop, the toner growth.

[0093] After freezing, the reaction mixture was heated to about
40.3° C., and the pH was about 7. The toner was quenched after
coalescence, and it had a final particle size of about 5.48 microns, a
volume average Geometric Size Distribution of about 1.26, and a
circularity of about 0.969.

[0094] A sample of the above toner slurry was taken and settled in a glass
vial. The sample had reasonably clear mother liquor, and toner having the
expected cyan color settled at the bottom.

[0095] Following the above synthesis, it was found that an organic based
pigment stayed in the latex particles. The pigment was thus incorporated
in toner particles successfully by aggregating the pigment containing
latex.

Example 3

[0096] Preparation of a latex with wax encapsulated in bio-resin
particles. About 69 grams of the bio based resin described above in
Comparative Example 1 was measured into a 2 liter beaker containing about
700 grams of dichloromethane. The mixture was stirred at about 300
revolutions per minute at room temperature to dissolve the resin in the
dichloromethane, thereby forming a resin solution.

[0097] About 36.45 grams of a polyethylene wax, commercially available as
IGI wax in a dispersion (about 30.37% by weight) and about 41.8 grams of
the cyan pigment dispersion described above in Comparative Example 1
(about 17% by weight containing 9 parts per hundred (pph) of the branched
sodium dodecyl benzene sulfonate surfactant from Tayca Corporation)
together with about 1.1 grams of sodium bicarbonate and about 2.94 grams
DOWFAX® 2A1, an alkyldiphenyloxide disulfonate (commercially available
from the Dow Chemical Company) (about 47% by weight) was measured into a
3 liter Pyrex glass flask reactor containing about 500 grams of deionized
water, thereby forming a water solution. Homogenization of the water
solution in the 3 liter glass flask reactor was commenced with an IKA
Ultra Turrax T50 homogenizer operating at about 4,000 revolutions per
minute. The resin solution was then slowly poured into the water
solution. As the mixture continued to be homogenized, the homogenizer
speed was increased to about 8,000 revolutions per minute and
homogenization was carried out at these conditions for about 30 minutes.

[0098] Upon completion of homogenization, the glass flask reactor and its
contents were placed in a heating mantle and connected to a distillation
device. The mixture was stirred at about 200 revolutions per minute and
the temperature of the mixture was increased to about 50° C. at a
rate of about 1° C. per minute to distill off the dichloromethane
from the mixture. Stirring of the mixture continued at about 50°
C. for about 150 minutes followed by cooling at about 2° C. per
minute to room temperature. The product was screened through a 25 micron
sieve. The resulting resin emulsion included about 14.26 percent by
weight solids in water.

Example 4

[0099] Preparation of EA toner with the wax encapsulated resin. About 3.59
grams DOWFAX® 2A1, an alkyldiphenyloxide disulfonate (commercially
available from the Dow Chemical Company) (about 47% by weight) and about
391.13 grams of the latex from Example 3 were added to a 2 liter glass
reactor equipped with an overhead stirrer. The mixture was cooled to
about 8° C. using an ice bath, and the pH was adjusted to about
4.2. About 46.79 grams of Al2(SO4).sub.3 solution (about 1% by
weight) was added as a flocculent under homogenization. The temperature
of the mixture was increased to about 17.1° C. with stirring at
about 300 rpm. The particle size was monitored with a Coulter Counter
until the core particles reached a volume average particle size of about
4.78 μm, with a GSDv of about 1.19. About 150.48 grams of the same
bio-based resin used in Example 3 in an emulsion (about 17.84% by weight,
with no wax or pigment) was added as shell, resulting in core-shell
structured particles having an average particle size of about 6.21
microns, and a GSDv of about 1.23.

[0100] Thereafter, the pH of the reaction slurry was increased to about 8
using about 3.62 grams EDTA (about 39% by weight) and NaOH (about 4% by
weight) to freeze, i.e., stop, the toner growth. After freezing, the
reaction mixture was heated to about 40.3° C., and pH was about 7.
The toner was quenched after coalescence, and it had a final particle
size of about 9.44 microns, and a volume average GSD of about 1.35.

[0101] Differential Scanning Calorimetry (DSC) of the toner sample showed
that about 11% of the wax was incorporated into the toner, compared with
9% of wax that was initially put in the toner formulation. Thus, after
aggregating the wax containing latex, DSC proved that the IGI
polyethylene wax was successfully incorporated into the toner.

[0102] It will be appreciated that variations of the above-disclosed and
other features and functions, or alternatives thereof, may be desirably
combined into many other different systems or applications. Also that
various presently unforeseen or unanticipated alternatives,
modifications, variations or improvements therein may be subsequently
made by those skilled in the art which are also intended to be
encompassed by the following claims. Unless specifically recited in a
claim, steps or components of claims should not be implied or imported
from the specification or any other claims as to any particular order,
number, position, size, shape, angle, color, or material.